If NWBO could have gotten TLD out in time for ASCO, I am pretty sure they would have done it there. When asked specifically about releasing data at ASCO during the ASM two years ago, Linda Powers replied: "ASCO is certainly a great venue and it's been great for us when the timing has worked out." So if the timing worked, they would almost certainly have presented at ASCO.
Now presenting there requires some advanced planning and they may not have been able to provide what ASCO needed in a timely manner to meet ASCO presentation deadlines, but that seems like a bit of a longshot to me.
ASCO is a giant meeting, even when virtual, of their targeted, professional audience. NWBO can't just replicate that on their own with some video conference. And if TLD is as good as expected, then it is going to overshadow anything else presented at ASCO or elsewhere this year.
People who said they spoke to NWBO management last fall about not presenting at SNO and other conferences reported being told that there were other conferences coming up and it seemed to suggest that their plan was to announce at a major conference (probably in conjunction with a journal article or something).
Trying to 'surprise' people with an announcement seems like a horrible idea to me. If anything, you want to broadcast it as widely as possible to generate as much enthusiasm as possible. The goal here is not to squeeze shorts, it is to get NWBO's name out to the public and provide the information necessary to the medical community who will be using this new SOC.
I doubt that the timing of warrant expiration is significant. There have been what, a half dozen extensions over the last 18 months or so? Each seems to indicate imminent news that never comes. Perhaps they optimistically think that they will be able to announce soon but they do not have a great track record in that regard. So personally, announcements about warrant-expiration extensions are meaningless to me.
The fact that they are not presenting at ASCO suggests to me that they are not announcing anything until at least July but then, who knows? Certainly not me.
(Note: although I specifically replied to marzan, I am covering a range of people's suggestions and comments.)